jeudi 26 juin 2014

Animals that don't Exist

The Bam-Bam Frog

The
bam-bam frog, Bombina Bambam, is
closely related to the European yellow-bellied toad, and is found most commonly
in southern Europe. Except for the crab-eating frog, Fejervarya cancrivora, it is the only known modern amphibian which
can live in saltwater. However, the crab-eating frog can only sustain short
excursion into ocean waters, whereas the bam-bam frog spends the entirety of its
life-cycle in the salty marches found on the Mediterranean shore. But its uncommon
habitat is not the most striking feature of this marvelous creature.

The
Mediterranean marshes are the ideal nesting places for a huge number of birds,
and also a preferred spawning ground for fish, crustaceans, and other marine
animals. As such, it is an extremely rich environment, abundant not only in
food, but also predators. To be able to survive in such a competitive
landscape, the bam-bam frog has pushed the characteristics of his ancestors to
the limit.

Frogs
are known for their well-developed hind legs, and the ensuing jumping power. In
the bam-bam frog, however, this feature has been polished to its peak. The hind
legs of the bam-bam frog make up as much as 90% of its total body mass, and
allow the frog to break the sound barrier. The maximum velocity of a jumping
bam-bam frog measured to this date is 398 m/s (1433 km/h or 888 mph). The loud “bang”
produced when the frog breaks the sound barrier also gave it its name. This
immense burst of speed, however, has two draw-backs, which evolution has
addressed rather elegantly.

The
sudden burst of speed, which allows the bam-bam frog to accelerate from zero to
the speed of sound in a few milliseconds, puts a tremendous strain on its
muscles, and its body is heavily compressed by the air in front of it. At the
same time, remaining in mid-air exposes it to the avian predators that can be
found in abundance in its habitat. To deal with this, the frog has developed a
number of mechanisms.

First,
in addition to an extremely stream-lined body, bam-bam frogs have a much
thicker layer of mucus on their skin than other amphibians, and their secretions
have a much higher viscosity than that of related species. Second, the bam-bam
frog has a loose flap of skin on its back.

Under
normal circumstances, the excess skin is held together by the mucus. However,
when the frog jumps, its muscles release a huge amount of lactic acid to
compensate for the effort. This acid, in turn, liquefies the mucus. The liquefied
mucus allows the frog to endure the rapid acceleration by absorbing the brunt
of the compression. As the mucus is stripped away by the air, the skin flap
becomes loose, and unfolds like a parachute, slowing down the animal. This
ensures that the frog can jump in a relatively small angle without excessive
risk of collision, which allows it to reduce the time it spends defenseless in
mid-air. This has caused the bam-bam frog to be known by another name, the
“paratroopers”.

Nonetheless,
it can happen that frogs jump straight up, in which case they are easy prey for
seagulls and other birds while the float gently back to the ground. In
Camargue, France, seagulls are known to follow herds of wild horses, waiting
until the mammals stumble upon a cluster of bam-bam frogs, and then feasting on
the stray frogs who have miscalculated the angle of their jump. It has also
been observed on numerous occasions that the loud noises of a startled group of
bam-bam frogs can attract predators from miles away.

Recent
studies suggest that in certain places, land and air predators seem to
collaborate in capturing the amphibians. Since the frog is less likely to jump
when there are birds in the air, snakes have been observed to hunt the frogs
more intensely when there are seagulls or other predators flying above. Whether
this collaboration is intentional or merely coincidental has yet to be
determined.